This invention relates to compositions which are mixtures of low friction materials and bondable materials and which are impregnated with bonding resins, and to bearings made from such compositions.
The prior art discloses low friction bearings made from mixtures of low friction materials and bondable materials, which mixtures are treated with bonding resins. U.S. Pat. No. 3,781,205 to Cairns & Walton discloses a bearing with a surface made from a combination of a solid lubricant and fibers which add dimensional stability. There is disclosed in U.S. Pat. No. 3,572,863 to Josephson a bearing made from a combination of asbestos fibers, phenol-formaldehyde resin, nitrate rubber, and a lubricant such as polytetrafluoroethylene. A bearing material made by applying a finely divided low friction material to fibrous substrate is described in U.S. Pat. No. 3,480,547 to Van Dyk. U.S. Pat. No. 3,464,845 to Osborn & Gobran discloses a bearing made from polyethylene sulfide resin and polytetrafluoroethylene and optionally other filler materials.
Such composite low friction bearings are often formed by molding. The following United States patents disclose bearing compositions that may be molded:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 3,994,814 Cairns 3,985,661 Ikeda & Ishikawa 3,908,038 Neinart, Saunders & Jeges 3,879,301 Cairns 3,779,918 Ikeda & Kawakita 3,583,913 Courtney 3,455,864 Dodson & White 3,000,846 Runton, Haddam & Morton ______________________________________
In such bearings there is a tendency of the low friction material and bondable material to separate from each other. In addition, it is desirable to have the low friction material and bondable material well mixed so as to give a rather uniform distribution of materials throughout the bearing.